1. Technical Field
This disclosure relates to a system and method for impact mitigation of sudden carrier frequency shifts in OFDM receivers.
2. Description of the Related Art
In a GSM mobile phone with an integrated DVB-H (digital video broadcast-handheld) receiver for mobile TV reception it is desirable to share a common reference clock for reduction of cost, size, and power consumption. Certain GSM mobile phone implementations tune the reference clock by a few Hz in order to adapt to the reference clock of the base station. This tuning of the reference clock may occur as sudden frequency jumps. As a consequence, the local oscillator frequency of the DVB-H receiver will jump by the same relative amount as the reference frequency. For DVB-H reception, the amount of frequency jump may be up to about ¼ of the sub-carrier spacing of the underlying orthogonal frequency division multiplexing (OFDM) transmission method. If this amount of frequency shift is not compensated for, it causes severe interference between adjacent OFDM sub-carriers, such that the error probability at the receiver increases dramatically, causing loss of information in the video stream.